Anterior shoulder instability with humeral avulsion of the glenohumeral ligament lesion

Humeral avulsion of the glenohumeral ligament (HAGL) is a rare lesion. The purpose of this study was to analyze the clinical manifestations of HAGL lesions in patients who underwent operative treatment for anterior shoulder instability. Six patients with HAGL lesions were studied. Four patients had an HAGL lesion associated with a Bankart lesion, and two had an isolated HAGL lesion. The range of motion at final follow-up showed a loss of 1 degree in forward flexion and of 15 degrees in external rotation. During an operation to treat anterior shoulder instability, a thorough examination for not only Bankart lesions but also other associated lesions, including an HAGL lesion, should be considered to lower the risk of redislocation. In repairing an HAGL lesion, the surgeon should keep in mind the possibility of a postoperative loss of external rotation and follow an active rehabilitation protocol to obtain successful results.     

The use of titanium mesh cages in the cervical spine.

Titanium mesh cages have been used widely for spinal reconstruction since 1986 when they first were introduced. Despite their popularity, relatively few studies have been published on their use in the cervical spine. These cages can be used as structural devices containing autologous local bone or iliac crest bone graft, obviating the need to harvest large structural bone grafts. The main disadvantages of their use are the increased costs and the difficulty of assessing fusion status. The authors review surgical techniques that can be used using titanium mesh cages in cervical spine applications and discuss some of their advantages and disadvantages.     

Can the Internal Iliac Artery Be Safely Covered during Endovascular Repair of Abdominal Aortic and Iliac Artery Aneurysms?

Aneurysmal involvement of the common iliac (CIA) or the internal iliac arteries (IIA) have been relative contraindications for safe endovascular aortic aneurysm (AAA) repair. Our goal was to review our experience in dealing with this problem by performing permanent coverage of one or both IIA during endoluminal repair of aneurysms of the aortoiliac region and to develop a safe, durable strategy. Of the 228 consecutive patients who had endoluminal repair of abdominal aortic (AAA) and iliac artery (IAA) aneurysms between 4/1999 and 4/2001 at our institution, 49 patients underwent coverage and/or coil embolization of one or both IIA during repair because of complex aortoiliac anatomy. These patients were evaluated prospectively for short-term adverse outcome. These results showed that CIA or IIA aneurysms can be managed safely during endoluminal repair of AAA. The IIA can be covered or embolized with minimum adverse consequences in patients who have inadequate CIA for deployment of the aortic or iliac endograft. Unilateral IIA occlusion is well tolerated. We advocate that whenever bilateral IIA occlusion is necessary during endovascular aneurysm repair, one of the IIAs should be revascularized if it is not aneurysmal.     

Modeling mechanisms of skull base injury for drivers in motor vehicle collisions.

OBJECTIVE: To develop biomechanical variable models for driver skull base injury mechanisms in motor vehicle collisions. STUDY DESIGN: Retrospective database review. METHODS: Biomechanical collision variables and safety restraint data were analyzed for Crash Injury Research and Engineering Network skull base trauma subjects enrolled during the recruitment period between 1996 and 2005. RESULTS: For drivers satisfying inclusion criteria (n = 26), injury resulted from contact with rigid vehicle structural elements in 82%, and occurred in 50% despite both seatbelt and air bags. Eight percent used neither seatbelts nor air bags. Seventy-two percent involved vector velocity changes greater than 30 mph. The relative morbidity of skull base injuries was also detailed. CONCLUSION: The majority of driver skull base injuries resulted from contact with rigid vehicle structural elements in high velocity crashes. Seatbelt and air bag use could not be definitively correlated with skull base injury. CLINICAL SIGNIFICANCE: Injury mechanism models can be developed that facilitate further investigations to determine impact and scope on a national scale.     

Extended rat-ear flap model: a new rodent model for studying the effects of vessel supercharging on flap viability

A new extended rat-ear flap model, with both an axial and a random component, is described. The flap is based on an axial supply by the posterior auricular artery and the posterior facial vein. The random portion, consisting of the rat dorsum, is capable of being supercharged at two separate sites-in the scapular and pelvic regions. There are several advantages to this composite flap. It is a combined axial and random flap. When used as a free flap, the viability of the axial portion serves as an indicator for anastomotic patency. The random portion allows for the investigation of the effects of pharmaceutical manipulation or surgical intervention, e.g., flap supercharging. The results indicate that the axial supply alone can cover approximately 50 percent of the extended rat-ear flap. Moreover, adding supercharging perforators to the random portion significantly increases the area of flap survival. Of interest, an axial vascular supply, coupled with more distal dorsal perforators (pelvic) than proximal (scapular) perforators, may increase survival for the so-called "watershed" area in the middle of the random portion of the flap. Additionally, this study also investigated the relative importance of arterial supply vs. venous drainage, using the extended rat-ear flap model. The flap was either supercharged with both the perforators of the scapular and pelvic arteries, or both scapular and pelvic veins. The results of the study suggests that augmenting venous drainage provides statistically significant improvement (87 percent vs. 51.6 percent) in increasing flap survival, when compared to augmenting the arterial supply. Arterial supercharging provided no improvement in flap survival, when compared to no supercharging (axial vessels + arterial supercharging, 51.6 percent vs. axial vessels alone, 49.9 percent). The results also suggest that providing adequate venous outflow is more important than providing additional arterial blood, and that impaired venous outflow may contribute to some cases of flap failure. However, it should be kept in mind that the best flap survival occurs with both arterial and and venous supercharging.     

Magnetic resonance appearance of bioabsorbable anchor screws for double row arthroscopic rotator cuff repairs

Background:

Little is known about the bioabsorbable, anchor related postoperative changes in rotator cuff surgery, which has become more popular recently. The purpose of the present study was to use magnetic resonance imaging (MRI) to analyze the degradation of bioabsorbable anchors and to determine the incidences and characteristics of early postoperative reactions around the anchors and their mechanical failures.

Materials and Methods:

Postoperative MRIs of 200 patients who underwent arthroscopic rotator cuff repair were retrospectively analyzed. The tissue reactions around the bioanchors included fluid accumulations around the anchor, granulation tissue formation and changes in the condition of the surrounding osseous structure. The condition of the bioanchor itself was also examined, including whether the bioanchor failed mechanically. In the case of mechanical failure, the location of the failure was noted. Serial MRIs of 18 patients were available for analysis.

Results:

The total number of medial row bioanchors was 124, while that of the lateral row was 338. A low signal intensity rim suggestive of sclerosis surrounded all lateral row bioanchors. Ninety three lateral row bioanchors (27%) showed a rim with signal intensity similar to or less than that of surrounding bone, which was granulation tissue or foreign body reaction (FBR). Similar signal intensity was seen around nine medial row bioanchors (7%). Fluid accumulation was seen around 4 lateral row bioanchors (1%) and around 14 medial row bioanchors (11%). Five lateral row bioanchors showed the breakage, while there was none in the medial row bioanchors. There were nine cases with a cuff re-tear (4.5%). There was no evidence of affection of glenohumeral articular surfaces or of osteolysis around any bioanchor. In serial MRI, there was no change in appearance of the bioanchors, but the granulation tissue or FBR around four bioanchors and the fluid around one bioanchor showed a decrease in successive MRI.

Conclusion:

This study highlights the normal and adverse reactions to Bioabsorbable anchors that surgeons can expect to see on MRI after rotator cuff repairs.     

Delayed paraplegia 10 months after endovascular repair of thoracic aortic aneurysm

Spinal cord ischemia after treatment of thoracic pathologies remains a devastating problem. A 74-year-old man with a history of infrarenal abdominal aortic aneurysm repair presented with bilateral common iliac and left femoral aneurysms as well as a thoracic aortic aneurysm. He underwent an open repair of the iliac and femoral aneurysms, followed by thoracic endovascular aneurysm repair in a staged manner without complications. Ten months later, he presented with hypotension, and permanent paraplegia developed.     

Adenovirus-mediated gene transfer of human inducible nitric oxide synthase in porcine vein grafts inhibits intimal hyperplasia.

OBJECTIVE: The aim of this study is to determine whether adenoviral inducible nitric oxide synthase (iNOS) gene transfer could inhibit intimal hyperplasia (IH) in porcine internal jugular veins interposed into the carotid artery circulation. METHODS: Porcine internal jugular veins were transduced passively with 1 x 10(11) particles of an adenoviral vector carrying either the human iNOS (AdiNOS) or beta-galactosidase (AdlacZ) cDNA for 30 minutes and then interposed into the carotid artery circulation. Segments of each vein graft were maintained in an ex vivo organ culture to measure nitrite accumulation, a marker of nitric oxide synthesis. The grafts were analyzed immunohistochemically for the presence of neutrophils, macrophages, and leukocytes by staining for myeloperoxidase, ED1, and CD45, respectively, at 3 (n = 4) and 7 (n = 4) days. Morphometric analyses and cellular proliferation (Ki67 staining) were assessed at 3 (n = 4), 7 (n = 4), and 21 days (n = 8). RESULTS: AdlacZ-treated vein grafts demonstrated high levels of beta-galactosidase expression at 3 days with a gradual decline thereafter. Nitrite production from AdiNOS-treated vein grafts was approximately fivefold greater than AdlacZ-treated grafts (P =.00001). AdiNOS or AdlacZ treatment was associated with minimal graft inflammation. Cellular proliferation rates were significantly reduced in AdiNOS-treated grafts as compared with controls at both 3 (41%, P =.000004) and 7 days (32%, P =.0001) after bypass. This early antiproliferative effect was most pronounced at the distal anastomosis (65%, P =.0005). The iNOS gene transfer reduced the intimal/medial area ratio in vein grafts at 7 (36%, P =.009) and 21 days (30%, P =.007) versus controls. This inhibition of IH was again more prominent in the distal segments of the grafts (P =.01). CONCLUSION: Adenovirus-mediated iNOS gene transfer to porcine internal jugular vein grafts effectively reduced cellular proliferation and IH. Although iNOS gene transfer reduced IH throughout the entire vein graft, the most pronounced effect was measured at the distal anastomosis. These results suggest potential for iNOS-based genetic modification of vein grafts to prolong graft patency.